To have decent insights into ancient Chinese wars, one should definitely have a close look at the Warring States Period in Chinese history, commonly referring to the era from 475 BC - 221 BC. This period was marked with endless brutal wars among warlords in an effort to annex smaller states around them and consolidate their rule.

By the 3rd century, seven major regional powers had risen to prominence, who competed each other toward the end of this period when the state of Qin became an unparallel power compared to the other six. Qin finally defeated them all and established the first unified empire in China in 221 BC.

In fact, the vicious struggles against barbarian threats and the many internal wars that China faced had contributed to the advancement of Chinese military techonology and strategy, of which Warring States Period was one notable example.

An advance in military technology in this period was the casting of individual weapons that allowed the arming of infantry soldiers. Previously, Chinese ancient wars were realised by aristocrats in chariots which then could not be produced on a mass production basis. Therefore, only a limited proportion of the population was to participate in the battles. With such development, states with economic resources could produce weapons and population to build large armies.

Consequently, complex logistical systems were needed to supply, train and control these large forces: the size of armies ranged something between tens of thousands to several hundreds of thousands of men. Military tactics thus changed: kingdoms fought by thowing masses of soldiers into each other, using a combination of calvatry and infantry while charriots gradually fell in disfavor. Siege warfare became more sophisticated.

Weapons were developed in quantity and quality. Iron was proliferated, replacing bronze in arms production. Most popular weapon among various ones used by infantry mean was the dagger-axe, various in shape, ranging from 9–18 ft in length. Crossbow was preferred as long range arm as mass production and mass training were possible. Battering rams were used to attack siege and shield against bows. Much large siege crossbow which could be fitted in wheeled carriage was developed. One of the models can shoot several large bolts at once, causing tremendous damage to enemy groups in tight formations.

The development in tactics and strategies used in Chinese ancient wars is even more significant. This chaotic and violent period also witnessed the emergence of many military strategists whose writings were about military organization, leadership, and battlefield tactics. Among them was the legendary Sun Tzu, the earliest international theorist and most influential miliary guide. Military strategy, as codified in his book “Art of War”, now shifted emphasis toward deception, intellengence and strategies. Planning was seen not as a to-do list but rather a quick response to the actual situation and physical environment.

A huge importance was placed on non-military means such as diplomatic, economic or political intrigue in the final victory. Until today, his military treatise is probably the most admired work dealing with the philosophy of military but also widely applied in non-military fields.